miR319a/TCP module and DELLA protein regulate trichome initiation synergistically and improve insect defenses in Populus tomentosa
miR319a/TCP module and DELLA protein regulate trichome initiation synergistically and improve insect defenses in Populus tomentosa
复制标题
miR319a/TCP模块和DELLA蛋白协同调节毛状体起始并提高毛白杨昆虫防御能力
DOI：
10.1111/nph.16585
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发表时间：
2020-05-12
期刊：
影响因子：
9.4
通讯作者：
Luo, Keming
中科院分区：
文献类型：
--
作者：
Fan, Di;Ran, Lingyu;Luo, Keming
毛状体是特殊的表皮细胞，有助于植物抵抗食草动物。它们的形成受到多种遗传和环境信号的精确控制。先前的研究表明，microRNA319（miR319）和赤霉素（GA）信号传导参与拟南芥毛状体的发育，但人们对这些因素之间的相互作用知之甚少。在此，我们报道了miR319a/TEOSINTE BRANCHED/CYCLOIDEA/PCF（TCP）模块与毛白杨中的GA信号协同参与毛状体的起始。我们证明，miR319a 的过度表达降低了其靶向 TCP 的转录水平，并显着提高了转基因杨树中的叶毛密度，导致昆虫食草性减少。相反，通过短串联靶标模拟物 (STTM) 抑制 miR319a 会提高转基因植物中的 TCP 表达水平并降低毛状体密度。通过引入 TCP19 的 miR319a 抗性形式，可以消除 35S:miR319a 植物的毛状体表型。此外，靶向 miR319a 的 TCP19 直接与 ga1-3 的抑制因子 (RGA) 相互作用，RGA 是 GA 信号传导的下游抑制因子。 TCP19和RGA协同抑制GLABROUS1 (GL1)诱导的毛状体标记基因GLABRA2 (GL2)的表达，从而抑制叶毛状体的起始。我们的结果提供了对miR319/TCP19模块和GA信号协调调节毛状毛状体起始的分子机制的深入了解。
Trichomes are specialized epidermal cells that contribute to plant resistance against herbivores. Their formation is controlled precisely by multiple genetic and environmental signals. Previous studies have shown that microRNA319 (miR319) and gibberellin (GA) signaling are involved in trichome development in Arabidopsis, but little is known about their interaction between these factors.Here we reported that the miR319a/TEOSINTE BRANCHED/CYCLOIDEA/PCF (TCP) module participates in trichome initiation synergistically with GA signaling in Populus tomentosa. We demonstrated that overexpression of miR319a decreased transcription levels of its targeted TCPs and significantly elevated leaf trichome density in transgenic poplar, resulting in decreasing insect herbivory. Conversely, repressing miR319a by short tandem target mimics (STTM) elevated TCP expression levels and decreased trichome density in transgenic plants.The trichome phenotype of 35S:miR319a plants could be abolished by introducing a miR319a-resistant form of TCP19. Furthermore, the miR319a-targeted TCP19 interacted directly with REPRESSOR OF ga1-3 (RGA), a downstream repressor of GA signaling. TCP19 and RGA synergistically inhibited the GLABROUS1 (GL1)-induced expression of trichome marker gene GLABRA2 (GL2), thereby repressing leaf trichome initiation.Our results provide an insight into the molecular mechanism by which miR319/TCP19 module and GA signaling coordinated regulating trichome initiation in P. tomentosa.